322 GASTEROPODA OF THE INFERIOR OOLITE. 
genus ; and Cossmann would still further enlarge its scope, since the latter author 
refers several of the species described by d’Orbigny under Straparollus to 
Solarium. Fischer, on the other hand, expresses doubts, observing that “ the 
numerous species [of Solarium] indicated in the Jurassic beds belong probably to 
the genus Straparollus.” Morris and Lycett described two species of Solarium 
from the Great Oolite; one of these (S. disculum) is, according to my views, a 
species of Straparollus. 
The small shells from the Inferior Oolite which I refer to Solarivm constitute 
a fairly distinct group in that series ; and one of them, S. swbvaricoswm, may fairly 
be regarded as a typical representative of the modern genus. 
255. SOLARIUM PISOLITICUM, sp. nov. Plate XXVI, figs. 6—8. 
Description : 
Diameter (average size) . 4mm. 
Height . : : : . 2°75 mm. 
Spiral angle : ior : 
Shell greatly depressed, moderately umbilicated; nucleus oblique. Number 
of whorls in the majority of specimens about five; the earlier ones convex and 
orbicular at the periphery, but the body-whorl is flatter and slightly angulated at 
the periphery. As regards ornaments, the extreme apicals appear to have been 
rather smooth, but a rich radial ornamentation is early developed, and this in the 
body-whorl is slightly decussated spirally, so as to form a series of closely-set 
nodose costee. 
The body-whorl is relatively large and bicarinated, and the radial ornamen- 
tation is carried as far as the anterior keel, which, as a rule, is less nodose than 
the upper one. Base full, rounded, and produced; it is provided with fine 
reticulate ornaments, which are gathered into a ring of tubercles at the edge of 
the umbilicus. 
Aperture trapeziform or subpentagonal. 
Relations and Distribution —This pretty little shell is easily distinguished 
from the majority of the species referred to Straparollus by its regular spire and 
sloping whorls, and also by the radial or axial character of the ornamentation. 
The very small specimen from Crickley (fig. 7) is believed to represent the 
earlier stage, when the periphery is extremely orbicular. The very large one 
(9 mm. in diameter) from the Pea-grit of Cleeve Hill may, on the other hand, be 
regarded as a megalomorph, where another whorl has been added. The usual 
or average form is tolerably abundant in the Pea-grit at Leckhampton. 
‘ 
